In order to predict more effectively the oil spill accident, a model to predict the influence of wharf oil spill accident of Nanjing section in the lower reaches of Yangtze River was set up based on EFDC (environmental fluid dynamics code). The study results show that the two dimensional hydrodynamic model set up can more accurately reflect the overall rules of the spilled oil spreading and migration in [JP2]Yangtze River under the comprehensive effects of wind field, flow field, complex terrain conditions of the study area, and the degradation of oil slicks in the study area is slow, and when the oil spill occurred in the ebb time and in the westerly wind, oil slicks diffuse to the downstream more early, resulting in a more serious pollution on the downstream protection zone.